At what stage are you at? If you are at the second stage of the install (after downgrading IOS15), then you did not follow the instructions correctly. Try again.
DO NOT use guides you find on GBATemp. While there's some good stuff there, many of them are outdated and dangerous, and it is very hard to tell the difference.
The GAF guide gives you everything you could need. You can either install a
USB Loader and play the game off a hard drive, or run the stuff to
avoid the disc updates. If the disc fails to load using either of those methods, then it is likely you need new IOSes. To get those, just run the
Safe 4.2 Updater. If your Wii is not connected to the Internet, there is an alternative I can tell you about.
Again, DO NOT use GBATemp guides without asking here first.